The Garmin Forerunner series is a range of devices designed for running. Specifications vary across the range, some are simple watches, others have more navigation features. None of them support mapping, but many support GPS tracelog exporting via USB mass storage and/or via Garmin Connect.

Note the Forerunner 50, 60 and 70 do not use GPS, they only work with a heart rate monitor, footpod or bike speed/cadence sensor.

The Forerunner 25 is an upgrade to the older Forerunner 15. It is similar, but it features a higher resolution 128x128 display and Bluetooth, allowing it connect to smartphones via Garmin Connect Mobile.

The Forerunner 205/305 fix many of the bugs and design flaws that plagued the 301. The unit uses the new SiRFstar III chip-set and positions the antenna better. It maintains satellite lock without problems in dense forests and built-up areas. The 305 differs from the 205 in the HR chest strap and support for an optional cadence monitor. The unit comes with a built-in Li-Ion battery that lasts around 10 hours between recharges. It connects via USB and comes with Garmin Training Center (Windows) which allows saving workouts in tcx format. It's also supported by gpsbabel and garmintools allowing readout of tracks in gpx-format. The "lap" button can function as a quick "waypoint" recorder but the device also supports proper waypoints (max. 100) via "mark location" in the navigation menu. The most significant limitation is the internal memory supporting only 13000 trackpoints which corresponds to 3,5 hours of recording in 1/sec mode.

At end of year 2009 it seems Garmin no longer markets Foreunner 205, the new equivalent seems to be Forerunner 405

Comparison to eTrex HCx

In direct comparison to the eTrex Vista HCx I've observed that the Forerunner 305 often performs better, i.e. has a much better accuracy.